The present invention relates to wireless digital networks, and in particular, to converting devices such as access points in a wireless network to spectrum monitors, and to RF spectrum management using spectrum information.
Wireless digital networks are becoming ubiquitous in enterprises, providing secure and cost-effective access to resources. Those networks usually have one or more controllers, each controller supporting a plurality of access points (AP) deployed through the enterprise. WiFi networks operating in accordance with IEEE 802.11 standards are examples of such networks.
Unfortunately, the frequencies used by these networks are shared. They are shared not only among the wireless networks themselves, but also with other non-network radiators. Non-network radiators, devices such as microwave ovens, wireless audio and video streaming devices, cordless phones, Bluetooth devices and the like, as well as other wireless networking devices, can cause interference with the operation of a network. Interfering devices can come and go, change their nature, and move around. As an example, replacing or adding a microwave oven in an employee lounge area can dramatically alter the interference present to a network. Wireless networks need the ability to detect, classify, and work around such interference sources.
In searching out sources of interference to a wireless network, various pieces of test equipment such as spectrum analyzers are used. A professional spectrum analyzer has a calibrated receiver of exquisite sensitivity, and is able to display and measure signals over a wide range of frequencies and amplitudes. They are also expensive and require a skilled operator. This places them outside the realm of the normal wireless network environment.
What a digital wireless network does have is a plurality of access points, each of which contains one or more antennas and radios, a combination of a transmitter and a receiver, designed to operate on the frequencies used for the wireless network. A wireless network may also have one or more air monitors (AM) and/or spectrum monitors (SMs), which in many cases are re-purposed APs. While these radios may not have the performance of a high quality spectrum analyzer, they are capable of collecting data on portions of the spectrum used by the network.
What is needed are tools in the wireless network to switch devices between AP or AM operation and Spectrum Monitor (SM) operation, and if possible to use these devices in hybrid AP/SM modes, providing information to a management process which operates the network in the presence of interference.